How to turn on mouseover tooltips in Visual Studio?

I am working my way through this course and I see that the instructor’s version of Visual Studio has some useful tool-tips that popup when mousing over bits of code that I don’t see on my version of Visual Studio 2017. I’d like to know how to turn that on as it would be helpful to me. I am currently using Visual Studio 2017 Enterprise edition (on Windows 10) with the Unity tool set installed.

Here is a screen shot of an example:

Thanks in advance for any help.

I can’t say exactly, but here’s a link to the MicroSoft Docs page on IntelliSense, what they call the feature: MicroSoft Docs - Using IntelliSense

Thank you, that link is very helpful. Much appreciated!